2) For the attributes in (a) find suitable nouns in (b):

a) 1. famous; b) 1. water;

2. boiling; 2. problem;

3. glass; 3. thermometer;

4. cold; 4. device;

5. scientif­ic; 5. bulb;

6. electrical; 6. scientist;

7. mercury 7. point

VI. 1) Translate the following word combinations:

temperature scale, lightning conductor, freezing point, human body, German-speaking countries, measuring in­strument, temperature difference, boiling point, atmospher­ic pressure, numerical data, mercury thermometer, elec­trical device

2) Use these word combinations in sentences of your own.

VII. Give synonyms for the following words:

to use, big, learned man, owing to, instrument, various.

VIII. Read the text and translate it into Russian.

History of thermometers

Placing a kettle full of cold water on the fire is quite an ordinary thing. This time we shall do it to carry out a simple experiment. Placing a finger into the kettle from time to time, we find that the water is gradually becoming hotter and hotter, until it boils at last. In scientific lan­guage we describe this phenomenon by saying that the tem­perature of the water is rising.

However, we need some more exact means of measuring the difference of temperature than our finger. In fact, the finger can give us neither exact information, nor nu­merical data.

As a matter of fact, the very first step in the develop­ment of heat engineering made it necessary to find a de­vice for indicating temperature and for measuring its changes. As is well known, the thermometer is the very instrument that serves this purpose.

As early as 1602, Galileo invented an air thermometer. It consisted of a glass bulb containing air and connected to a glass tube, the latter being immersed into a coloured liquid. Galileo's air thermometer was sensitive not only to temperature changes but also to changes of atmospheric pressure.

The type of thermometer familiar to everyone at pre­sent was first put into general use as early as 1654. Making the first measuring instruments was not an easy thing at all. Needless to say, the most difficult problem of all was that of marking the degrees on the thermometer, in other words, of graduating the scale. It was decided, at last, to take two fixed points and to divide the interval between them into small equal parts or degrees. And then, in 1701, Isaak Newton, the famous English scientist, whose name is known all over the world, constructed a scale in which the freezing point of water was taken as zero and the temperature of the human body as 12°.

Some time later the German physicist

Fahren­heit proved that the temper­ature of boiling water was always the same at the same atmospheric pressure. It might therefore be used as a second fixed

point instead of the temperature of he human body.

As for the liq­uid used, it was mercury which has been

mostly em­ployed since that time.

On the Fahrenheit scale the boiling point of water is taken as 212° and the freezing point as 32°, the interval being divided into 180 equal parts. The scale under consideration is indi­cated by writing the letter F after the temperature, as for example, 212°F. This scale is mainly used in .English-speaking countries.

So far we have not mentioned the Centigrade scale (see Fig. 2). On the Centigrade scale the freezing point of water is marked 0°C and the boiling point is marked 100°C, the let­ter C indicating this scale. This temperature scale is em­ployed in Russia as well as in most other countries of the world.

Speaking of thermometers, one must make reference to the pyrometer. We know of its being used for measuring temperatures that are too high for mercury thermometers. We also know of its finding wide application in industry.